Computer housing and expansion card format for consumer electronics devices

ABSTRACT

A computer housing and expansion card design facilitates the addition and removal of expansion cards from the front of a computer housing without disassembly of the housing, and further facilitates the connection of external cables to the expansion cards from the back of the computer housing.

FIELD OF THE INVENTION

The present invention relates to the field of computer enclosure design.Specifically, the present invention relates to a computer enclosuredesign and a complementary expansion card design to allow the additionand removal of expansion cards from the enclosure by an untrained userwithout requiring any disassembly of the enclosure.

BACKGROUND OF THE INVENTION

Computing devices, such as Personal Computers, are now commonplace inthe consumer market. Unfortunately, the current state of the art inenclosure and expansion card design requires considerable expertise andtime on the part of the user to change or upgrade the functionality ofsuch devices. Although some designs allow for the upgrade procedure tobe accomplished using common household tools, and even without tools,invariably they all require at least partial disassembly of the housing.

In the industrial and telecommunications markets, computer enclosures ofrack-mount type are used. Rackmount enclosures typically consist of afive-sided box with the front vertical face open to accept expansioncards. A backplane having a number of sockets is usually installed inthe back of the unit, parallel to the back vertical wall. Expansioncards are installed from the front, guided by rails or similarmechanisms, and engage sockets on the backplane when fully seated. Allconnections for external cables are placed at the front of the unit, onthe front bezel of each expansion card. Disk drives with removablemedia, such as floppy drives, are often placed directly onto expansioncards providing direct access to the media and eliminating the need forcables. The designs using rack-mount enclosures includeindustry-standard computers based on busses such as VME and others, andprovide excellent accessibility to expansion cards without requiringenclosure disassembly. Unfortunately, the fact that all external cablesattach to expansion cards from the front of the enclosure renders therack-mount enclosure type unacceptable for the office and homemicrocomputer market, both from cosmetic, ergonomic and safetystandpoints.

One of the driving requirements for the desktop computer market is thatof the ability to attach additional external cables to the back of thecomputer enclosure. This places such cables out of sight, reducesdesktop clutter, and prevents accidental disconnection by the user. Allthe solutions currently available in the office and home microcomputermarkets, including those based on industry-standard busses such as ISA,PCI, NuBus and Micro Channel, approach this problem in essentially thesame manner. The typical microcomputer enclosure is a six-sided boxconstructed of at least two major parts, a chassis and a cosmetic cover.The back vertical wall of the chassis features openings through whichconnectors on expansion cards may be accessed. A backplane or amotherboard is installed in the chassis perpendicular to the backvertical wall and features a plurality of sockets for acceptingexpansion cards. The expansion cards of prior art typically comprise abus connector located along one edge of the card and optional electricalconnectors for the attachment of external cables located along anadjacent, perpendicular edge of the card. A metal bezel is typicallyutilized on expansion cards to block the portion of the opening in theback vertical wall of the chassis that is not utilized for accessingelectrical connectors on the card. When a card having electricalconnectors is installed in a socket on the backplane, the electricalconnectors on the card can then be accessed through an opening in theback vertical wall of the chassis.

The process of installing expansion cards involves four major steps.First, the cosmetic cover is removed from the chassis. Second, anopening in the back vertical wall of the chassis is exposed by removinga metal bracket or cover plate. Third, an expansion card is installedperpendicular to both the backplane and the back vertical wall of thechassis by inserting said card into an appropriate socket on thebackplane so that the bezel of the expansion card aligns with theopening in the back vertical wall exposed in step two. Step fourinvolves the installation of the cosmetic cover back onto the chassis.

The typical microcomputer enclosure is further complicated by the factthat disk drives with removable media are best accessed from the frontof the enclosure. To facilitate such access, the majority ofmicrocomputer enclosures incorporate separate drive bays at the front ofthe unit. The placement of the drive bays at the front of the enclosurerequires the use of cables to provide electrical connections between thedrive and the drive controller card. A disk drive is installed in atypical microcomputer chassis, with or without special adapter brackets,in a five-step process. Step one involves the removal of the cosmeticcover from the chassis. In step two, a blank bezel is removed from thecosmetic cover to allow subsequent access to the disk drive. The thirdstep consists of the installation of the disk drive in a drive bay.Extra steps may be required at this point to install a drive controllercard in an expansion slot, if one is not already present. Then, in stepfour, the necessary cables are connected between the drive and the drivecontroller card, and also the power supply. In step five the cosmeticcover is installed back on the chassis.

As can be seen from the above description, the microcomputer chassisdesigns of the prior art achieve the placement of external cableconnections on the back of the enclosure at the expense of significantcomplexity in terms of both design and serviceability.

Due to the rapidly changing nature of the computer market, the abilityto easily upgrade the functionality of computing devices is essential inmaintaining their usefulness. As more and more computing devices findtheir way into the homes of consumers who lack technical training, theease with which these devices can be upgraded becomes a major factor indetermining their useful life.

In addition to the difficulties in upgrading and service, the designcomplexity of existing microcomputer enclosures results in considerableexpense to the manufacturer in terms of raw materials, tooling, andmanufacturing cost, diminishing the manufacturer's overall ability tocompete in the marketplace.

What is needed is a new design to allow computing devices that can beupgraded easily in the field by untrained consumers and that can bemanufactured efficiently with the minimum number of parts and assemblysteps. The present invention possesses several new and unique featuresto enable it to meet these goals.

SUMMARY OF THE INVENTION

The main objective of the present invention is to provide a computerenclosure and expansion card design which facilitates the installationand removal of expansion cards from the front of the enclosure withoutdisassembly of said enclosure, and also allows the attachment ofexternal cables to installed expansion cards from the back of theenclosure. A computer enclosure apparatus and a complementary expansioncard design are disclosed herein that achieve this objective. Within thecontext of the invention, the term `computer` means any electronicdevice for processing digitally encoded information.

The computer enclosure has a back wall having a plurality of openings,equal in number to the maximum number of expansion cards the enclosureis designed to receive, and also has a backplane with a plurality ofsockets to accept expansion cards. The sockets are equal in number tothe openings and are spaced the same distance apart as the openings. Thebackplane is mounted in the enclosure parallel to the back wall, and issized and aligned so as not to block any of the openings, and so thateach of said plurality of sockets is juxtaposed to and substantiallyaligned with exactly one of the openings. The computer enclosure of thepresent invention is configured to receive expansion cards forinstallation from the front of the enclosure. The enclosure mayadditionally incorporate structure for slidingly receiving the expansioncards, as well as latching structure to facilitate installation,positive retention and removal of the expansion cards.

The expansion card of the present invention includes a printed circuitboard, a bus connector positioned along the back edge of the expansioncard to engage one of the sockets on the backplane, and a connector forthe attachment of external cables to the expansion card. The connectoris positioned along the same (back) edge of the expansion card as thebus connector, and aligned so as to be accessible from the back of theenclosure through the appropriate opening in the enclosure back wallwhen the expansion card is installed in a socket on the backplane of thecomputer enclosure. Optional indicator lights, switches and removablemedia receptacles are positioned along the opposite (front) edge of theexpansion card so as to be accessible from the front of the enclosure.An expansion card assembly is possible utilizing a small-size printedcircuit board mounted on a metal frame, said frame sized andproportioned so as to facilitate installation in the computer enclosureof the present invention, and the printed circuit board mounted on theframe so as to align with a socket on the backplane and an opening inthe enclosure back wall when the expansion card assembly is installed inthe enclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention, its configuration, construction, and operation will bebest further described in the following detailed description, taken inconjunction with the accompanying drawings in which:

FIG. 1 is an exploded perspective view showing the enclosure back wallof the invention having a plurality of openings, the backplane of theinvention having a plurality of sockets and an expansion cardinterconnectable therewith;

FIG. 2 shows the components of FIG. 1 assembled together in accordancewith the present invention;

FIG. 3 is a perspective view showing the assembly in FIG. 2 from theback;

FIG. 4 is an exploded perspective view of an expansion card shown inFIGS. 1-3;

FIG. 5 shows the assembled expansion card of FIG. 4 from a backperspective view;

FIG. 6 is a front perspective view of the assembly in FIG. 5;

FIG. 7 shows an expansion card bracket supporting a small-format printedcircuit board, a disk drive and a front bezel; and

FIG. 8 is a perspective view of the enclosure of the present inventionfeaturing the enclosure back wall and side walls.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The preferred embodiment of the present invention is a low-costupgradeable home computer. A computing device intended for the consumermarket places an equally high premium on cosmetic appearance, ease ofuse and low cost, and therefore stands to derive the most benefit fromthe innovations of the present invention.

The essential components of the invention are illustrated in FIG. 1. Anenclosure back wall 1 is an important part of a complete enclosure,which in the preferred embodiment is a five-sided box with the frontface open in order to receive expansion cards. The specific features ofenclosure back wall 1 that are particular to the present invention are aset of openings 4 that will allow access from the outside to installedexpansion cards on the inside. In addition, the back wall 1 will allowthe mounting of a backplane 2 parallel to the enclosure back wall 1.Other means of mounting the backplane 2 parallel to the back wall 1 arepossible that are not part of the enclosure back wall 1 but are insteadincorporated into other parts of the computer enclosure. A number ofcomputer enclosure designs are known in the prior art that featureaccess openings in the enclosure back wall, however the backplane ormotherboard in these designs is mounted perpendicular to the enclosureback wall. By specifying that the backplane 2 is mounted parallel to theenclosure back wall 1 the teachings of the present invention enable thekey benefits of being able to install and remove expansion cards fromthe front of the enclosure and being able to attach external cables toexpansion cards from the back of the enclosure.

The main supporting structure is a printed circuit board 3. This is ahorizontal member which will support electronics of the device which isbeing installed. Note that the backplane 2 has a plurality of sockets 5which will connect with a bus connector 6 located on the printed circuitboard 3. Bus connector 6 shown is of the card-edge type. Bus connector 6may be of the right-angle box type, in addition to a surface-mount type,in addition to any of a number of known types. Adjacent the busconnector 6 is a connector 7 intended to facilitate connection betweenthe printed circuit board 3 and its associated electronics and pointsremote with respect to the present invention. A metal back bezel 8surrounds the connector 7 and accomplishes several functions. The bezel8 provides support and stability to the connector 7. The bezel 8 furtherprovides a sealing and finishing structure with respect to the pluralityof openings 4. This will help where the enclosure of the presentinvention is being cooled under directed air flow, and also for theprevention of dust from entering and coming into contact with theelectronics carried on the printed circuit board 3.

At the other end of the printed circuit board 3, a front bezel 9 issupported, and shown with an indicator light 10. It is understood thatthe indicator light 10 may exist in multiple numbers depending upon theelectronics carried by the printed circuit board 3, as are necessary toindicate functionality to the user.

The expansion card illustrated in FIG. 1 is one of many designs that maybe constructed in accordance with the present invention. Additionalexamples of such designs are shown in FIG. 4, FIG. 5, FIG. 6 and FIG. 7.In FIG. 4, an exploded view of a CD-ROM expansion card is shown. ACD-ROM drive 11 is shown mounted directly onto the printed circuit board3.

FIG. 5 illustrates a rear view which specifically shows the connectorspecifics of connector 7, as well as the assembled version of the CD-ROMexpansion card of the present invention. FIG. 7 illustrates a slightlydifferent version where the expansion card bracket 12 carries both adisk drive 13 and a small-format printed circuit board 14. This assemblymeets the parameters of expansion card design under the presentinvention, having a bus connector 6 and a connector 7 co-located on thebackfacing edge of the assembly. Thus, as is shown, there can exist alarge variety of possible combinations for the expansion card of thepresent invention. Other structures can include floppy disk drives andother receptacles of removable computer media, such as memory cardsockets, to be easily mounted to printed circuit board 3 and be madeaccessible through appropriate apertures in front bezel 9. This allowsthe combination of the entire storage subsystem, including the drive,the controller electronics, the means for interconnecting the controllerto the drive, and all mounting hardware into one easily serviceableassembly.

The important feature of expansion card design under the presentinvention is the co-location of the bus connector 6 and connector 7substantially on the same edge of the printed circuit board 3, the edgethat faces towards the back of the enclosure when the expansion card isinstalled in the enclosure. This co-location of the two componentsenables the bus connector 6 to engage a socket 5 on the backplane 2 uponthe installation of the expansion card in the enclosure, andsimultaneously makes connector 7 accessible through a correspondingopening 4 in the enclosure back wall 1 for the purpose of attachingexternal cables. To meet cosmetic and emissions requirements, a metalback bezel 8 and a plastic front bezel 9 are further incorporated intothe design of the expansion card. As required, the front bezel 9 mayfeature an additional EMI shield, many forms of which are known in theart. The indicator light 10 may be placed on the printed circuit board 3so as to be visible through a corresponding aperture in front bezel 9,and so on.

The enclosure design is further illustrated in FIG. 8, having side walls15 and incorporating a set of card guides 16 to slidingly receiveexpansion cards. A complete enclosure of the present invention will alsoincorporate a top wall and a bottom wall, which have been omitted fromthe illustration in FIG. 8 for clarity of presentation, as said top andbottom walls are not essential to the present invention but serve thepurposes of providing mechanical stability, improving the cosmeticappearance and providing EMI shielding.

The structures used to assemble the structures shown in FIGS. 1-8 can beany method calculated to provide long life and serviceability. Forexample, in FIG. 1, the backplane 2 is attached to the back wall 1 byuse of set off structures 17 to permit the use of screws or rivets toattach the backplane 2, yet not force the surface of backplane 2 againstthe back wall 1. Other types of attachment are equally acceptable bothfor the backplane 2 and all other structures.

The description presented herein is illustrative and not limiting. Otherembodiments will become apparent to those skilled in the art in light ofthe teachings of the present invention. Such embodiments may include theincorporation of all or part of the apparatus of the present inventioninto improved versions of existing products, such as television sets andother appliances.

What is claimed is:
 1. A back wall assembly for a computer enclosurecomprising:a back wall having a plurality of openings; and a backplanehaving a plurality of sockets to receive a plurality of expansion cardseach having a connector for attachment of a cable, each said socketassociated with a single one of said openings in said back wall, saidbackplane supported parallel to said back wall and spaced apart fromsaid openings in said back wall to allow direct access to said connectoron said expansion card through its associated one of said openings.
 2. Aback wall assembly for a computer enclosure comprising:a back wallhaving a plurality of openings; a backplane having a plurality ofsockets, each said socket associated with a single one of said openingsin said back wall, said backplane supported parallel to said back walland spaced apart from said openings in said back wall; a pair of sidewalls connected to said back wall, parallel to each other andperpendicular to the back wall; and expansion card guide means toslidingly receive expansion card, supported by said pair of side walls,said expansion card guide means aligned with said openings in said backwall and with said sockets on the backplane.
 3. A computer enclosure asrecited in claim 2 and further comprising:an expansion card supported bysaid expansion card means and having a bus connector in electricalcontact with an associated one of said sockets and having a connectorfor attachment of external cables, said expansion card having a frontbezel evenly fittable with respect to said pair of side walls while saidbus connector is in electrical contact with said associated one of saidsockets.
 4. A computer enclosure as recited in claim 3 wherein saidexpansion card guide means enables said bus connector of said expansioncard to approach an associated said socket of said back wallsimultaneously as said connector approaches an associated said back wallopening.